Umbilicus and the rectus sheath: a study using human fetuses.

PURPOSE: The newborn umbilicus is provided by a fibrous ring after closure with a scar at the bottom. Since it is believed to be embedded in the linea alba, a specific connection with the rectus sheath was not yet hypothesized for the umbilicus. However, there are no or few descriptions about the development and growth. METHODS: We histologically examined 28 fetuses at 8-40 weeks: 6 fetuses at 8 weeks, 12 at 10-14 weeks and 10 at 31-40 weeks. RESULTS: An initial rectus sheath issued a linear mesenchymal condensation toward the umbilical cord at 10-14 weeks and, an established sheath provided a fibrous band around the umbilical cord at 31-40 weeks. The rectus sheath margins made an acute turn toward the skin at the superior and lateral rims of umbilicus and dispersed into a loose tissue of the cord. In contrast, the sheath margin changed its direction gradually to the superficial side at the inferior rim and inserted at a border between the skin epidermis and a mesothelium-like covering of the cord. The developing umbilical ring contained no or few elastic fibers. CONCLUSION: Instead of the underdeveloped linae alba, the rectus sheath seemed to be tightly connected with the umbilicus at birth. Rather than an expected elasticity, the rectus muscle contraction was likely to play a critical role in the closure after birth. Via the umbilical ring, the fetal rectus sheath also seemed to tightly connect with the skin at the inferior rim of umbilicus.

Anatomy and embryology of umbilicus in newborns: a review and clinical correlations.

Umbilicus is considered a mirror of the abdomen in newborns. Despite its importance, the umbilicus has been stated in literature and textbooks as discrete subjects with many body systems, such as the urinary, digestive, and cardiovascular ones. This article aimed to address the basic knowledge of the umbilicus in relation to clinical disorders under one integrated topic to aid physicians and surgeons in assessing newborns and infants. The umbilicus appears as early as the fourth week of fetal life when the folding of the embryonic plate occurs. The umbilicus appears initially as a primitive umbilical ring on the ventral aspect of the body. The primitive umbilicus contains the connecting stalk, umbilical vessels, vitelline duct and vessels, allantois, and loop of the intestine. Changes occur to form the definitive cord, which contains three umbilical vessels, namely, "one vein and two arteries," embedded in Wharton's jelly. After birth, the umbilical vessels inside the body obliterate and gradually form ligaments. Congenital disorders at the umbilicus include herniation, bleeding, and discharge of mucous, urine, or feces. Some of these disorders necessitate emergent surgical interference, whereas others may be managed conservatively. The umbilicus has many embryological remnants. Thus, the umbilicus is prone to various clinical disorders. Detecting these disorders as early as possible is essential to prevent or minimize possible complications.

Evolution of congenital malformations of the umbilical-portal-hepatic venous system.

OBJECTIVE: The objective of this study is to describe the evolution of 8 cases of congenital malformations of the umbilical-portal-hepatic venous system diagnosed before the first month of life. MATERIALS AND METHODS: All cases of congenital malformation of the portal and hepatic venous system diagnosed prenatally or during the first month of life in our institution were systematically reviewed since November 2000. Clinical features, imaging, and anatomical findings were reviewed, focusing primarily on clinical and radiologic evolution. RESULTS: Eight cases of congenital malformation of the umbilical-portal-hepatic venous system were studied. Fifty percent of these malformations were diagnosed prenatally. We report 4 portosystemic shunts. Three involuted spontaneously, and the fourth one required surgical treatment. We report a variation of the usual anatomy of portal and hepatic veins that remained asymptomatic, an aneurysmal dilatation of a vitelline vein causing portal vein thrombosis that needed prompt surgical treatment with good result, a complex portal and hepatic venous malformation treated operatively, and a persistent right umbilical vein that remained asymptomatic. CONCLUSION: Prenatal diagnosis of malformations of the umbilical-portal-hepatic venous network is uncommon. Little is known about the postnatal prognosis. Clinical, biologic, and radiologic follow-up by ultrasonography is essential to distinguish pathologic situations from normal anatomical variants.

Pathogenic implications of remnant vitelline structures in gastroschisis.

PURPOSE: The pathogenesis of gastroschisis is unknown. It may be helpful in understanding its pathogenesis to know the structural relationships among umbilical components including umbilical vessels, urachus, and vitelline structures, and thus, the authors investigated the remnants of vitelline structures in a series of cases of gastroschisis. METHODS: Medical records of 41 cases with gastroschisis treated in our institute from 1979 to 2009 were retrospectively reviewed. RESULTS: Paraumbilical bands, possible remnants of vitelline structures, were observed in 4 cases (9.8%). All 4 bands were attached to the skin edge of the abdominal defect without incorporation into the umbilical cord. The band ended at the mesentery in 3 cases and at the antimesenteric site of the ileum in the remaining case. Histologic findings showed fibrous tissues in all cases. One was possibly associated with the development of colonic atresia. Another was noticed after silo reduction when herniated bowels became strangulated by the band. The other 2 cases were uncomplicated. CONCLUSIONS: Our findings may support the recently proposed hypothesis that the developmental failure of the yolk sac and related vitelline structures to merge with or to be incorporated into the umbilical stalk might be associated with the pathogenesis of the abdominal wall defect in gastroschisis. Paraumbilical bands derived from vitelline structures may possibly cause intestinal ischemia prenatally or postnatally.

[The wet umbilicus: maybe not an umbilical granuloma?]. / De nattende navel: misschien geen navelgranuloom?

Three infants, 1 girl aged 10 months and 2 boys aged 2 and 4 months, presented with a discharging umbilicus directly or shortly after birth. Echography and cystography showed three different causes: a cystic remnant of the omphalomesenteric duct, a persistent urachus and a persistent omphalomesenteric duct. All were successfully managed surgically. The most common cause of a discharging umbilicus is an umbilical granuloma. This is usually treated by application of silver nitrate. In some patients, however, the discharge may not disappear or may contain urine or faecal material. These cases should be referred and echography performed. In case of an anomaly of the urachus or the omphalomesenteric duct, surgical exploration is mandatory. The lesion should be excised en bloc, together with a part of the bladder or the bowel.

A novel navel presenting as an umbilical polyp and urachal sinus associated with an epigastric cleft: a clue to anterior midline fusion defects.

Umbilical and periumbilical disorders may present with a diverse group of anomalies and reflect the developmental embryological events they result from. A rare occurrence in a newborn of an umbilicus with an umbilical polyp together with an urachal sinus associated with a supraumbilical abnormal skin area known as epigastric cleft is reported herein, to help to elucidate embryological steps of anterior midline fusion defects and urachal remnants.

The Pitx2 protein in mouse development.

The Rieger syndrome, an autosomal dominant disorder involving ocular, dental, and umbilical defects is caused by mutations in PITX2, a Bicoid-type homeobox protein. Mouse Pitx2 mRNA is expressed in eye, tooth and umbilicus consistent with the human Riegers phenotype. Moreover, Pitx2 is involved in the Nodal/Sonic hedgehog pathway that determines left/right polarity. In this report we demonstrate a 32-kDa polypeptide on Western blots of nuclear extracts from a rat pituitary cell line, using a Pitx2 specific antibody (designated P2R10). We describe also for the first time expression of the Pitx2 protein in mouse. Pitx2 protein immunostaining was detectable during the development of the eye, tooth, umbilicus, and also in the pituitary, heart, gut, and limb. We demonstrate for the first time directly that Pitx2 is asymmetrically expressed in early heart, gut, and lung development.

Pediatric umbilical problems.

After birth, the normal umbilicus is a relatively simple structure. During the development of the embryo, however, this region is highly complex. Vestigial of the umbilical cord can be responsible for umbilical inflammation and drainage. This article reviews the embryology of the umbilicus and discusses a number of clinical problems seen in this area. The authors' aim is to aid the primary care pediatrician in evaluating, treating, and appropriately referring umbilical problems encountered in office practice.

Failure of ventral body wall closure in mouse embryos lacking a procollagen C-proteinase encoded by Bmp1, a mammalian gene related to Drosophila tolloid.

The mouse bone morphogenetic protein1 (Bmp1) gene encodes a secreted astacin metalloprotease that cleaves the COOH-propeptide of procollagen I, II and III. BMP-1 is also related to the product of the Drosophila patterning gene, tolloid (tld), which enhances the activity of the TGFbeta-related growth factor Decapentaplegic and promotes development of the dorsalmost amnioserosa. We have disrupted the mouse Bmp1 gene by deleting DNA sequences encoding the active site of the astacin-like protease domain common to all splice variants. Homozygous mutant embryos appear to have a normal skeleton, apart from reduced ossification of certain skull bones. However, they have a persistent herniation of the gut in the umbilical region and do not survive beyond birth. Analysis of the amnion of homozygous mutant embryos reveals the absence of the fold that normally tightly encloses the physiological hernia of the gut. At the electron microscopic level, the extracellular matrix of the amnion contains collagen fibrils with an abnormal morphology, consistent with the incorporation of partially processed procollagen molecules. Metabolical labelling and immunofluorescence studies also reveal abnormal processing and deposition of procollagen by homozygous mutant fibroblasts in culture.

[A bizarre excrescence of the umbilicus in a 1-month-old child]. / Une excroissance bizarre de l'ombilic chez un enfant de un mois.

We report the case of an umbilical polyp, derived from omphalo-mesenteric remnants in an one-month-old female child. This rare abnormality results from a closure defect of the vitelline duct. The vitelline duct normally closes between the 5th and the 7th weeks of intra embryonic development but can lead to several pathologies in case of closure defects, giving rise to abdominal (Meckel diverticulum, vitelline cyst) or umbilical symptoms (umbilical fistula, umbilical sinus and umbilical polyp). These disorders have a 2% incidence, and may induce clinical symptoms of varied gravity ranging from clinical silence to acute abdomen. We seized the opportunity of this rare clinical observation to review the nosology of vitelline duct defects at the light of embryologic data.

Umbilical discharge: a review of 22 cases.

Umbilical discharge is a symptom of a varied pathology. We analysed the files of 22 patients with umbilical discharge operated on in our hospital over a period of 23 years. In 13 patients the umbilical discharge was accompanied by an acute umbilical inflammation. In 10 patients the symptoms were caused by embryonic anomalies and in 12 patients by an acquired pathology. We propose a surgical technique that can be applied regardless of the pathology, and that does not involve a pre-operative assessment of the causes.

Umbilical inflammatory conditions: case report and differential diagnosis.

Umbilical inflammatory conditions may result from a variety of congenital and acquired abnormalities, some of which may be life threatening. An understanding of the developmental anatomy of the umbilicus provides a basis for formulating an approach to both evaluation and treatment of these conditions. A case report is presented.

Umbilical polyps.

We report three patients, ages 5 years, 3 years, and 4 days, with umbilical polyps. In the third child the polyp was associated with an umbilical enteric fistula. An umbilical polyp is the result of incomplete closure of the omphalomesenteric duct and becomes apparent after the umbilical cord is detached. It is a reddish tumor of a few millimeters; it seldom bleeds or is exudative. We consider it important to study every case in detail in order to exclude possible underlying embryologic anomalies such as Meckel's diverticulum and umbilical enteric fistula.

Clinical diagnosis of umbilical swellings and discharges in children.

Umbilical swellings and discharges are frequently seen in paediatric practice. Whereas the diagnosis of umbilical hernia and the much rarer conditions of exomphalos and gastroschisis should not be problematic, urachal and vitello-intestinal tract remnants that require surgery may resemble the common umbilical granuloma, which may be treated with silver nitrate. A comparison is made of the features of cases that required admission to the Royal Children's Hospital, Melbourne, for umbilical problems from 1973 to 1985, inclusive. A diagnostic protocol to assist the attending primary care physician is suggested.

[An unusual form of laparoschisis. Contribution to the embryological study of the umbilical region]. / Une forme particulière de laparoschisis. Contribution à l'étude embryologique de la région ombilicale.

The authors report one case of laparoschisis with special anatomic peculiarities: it was not defect on the abdominal wall, the intestinal evisceration go through a cordonnal defect who was distand of the normal abdominal wall and umbilicus. This observation re-opens the whole question of the abdominal wall deformities and all the embryologic theories are discussed.

[Gastroschisis and omphalocele in the same family (author's transl)]. / Laparoschisis et omphalocèle dans une même famille.

Occurrence of gastroschisis and omphalocele in the same sibship reported for the first time. After a first case of gastroschisis, it is advisable to measure the alpha-fetoprotein level in the maternal serum and to perform diagnostic ultrasonography in the next pregnancy in order to make a prenatal diagnosis. The authors suggest the existence of a similar anomaly of the umbilical ring.

Clinical anatomy of the umbilicus.

The diagnostic value of the appearance of the umbilicus in a wide range of conditions is discussed. Umbilical sepsis, tumours, fistulas, developmental anomalies and hernias are described, and the embryology of related structures is outlined.

Umbilical anomalies.

During intrauterine development the primordia of the developing gastrointestinal and urinary tract come into close proximity in the umbilicus where the communication of these structures with the external environment is usually obliterated. In a small percentage of patients the omphalomesenteric duct and/or urachus may remain completely or partially patent. When complete patency is present, drainage of mucus, stool, or urine may occur. Partial patency may be manifest by an abdominal mass or by no symptoms at all. Definitive treatment includes total excision of the omphalomesenteric duct and/or urachus, lest recanalization of remnant tissue or carcinoma in later life occur.

Gastroschisis: no myth.

The question has been raised whether omphalocele and gastroschisis are fundamentally different pathologic entities, or whether they are only different manifestations of the same underlying cause. After studying the family history of 37 patients with omphalocele and 14 patients with gastroschisis, it seems probable that hereditary factors contribute to the origin of omphaloceles. Such factors were not shown in patients with gastroschisis. Therefore genetic evaluation and counseling is advocated for the parents of a child with omphalocele.